Motor-vehicle.



H. D. CHURCH.

MOTOR VEHICLE.

APPLICATION FILED NOV. 13, 1913.

Patented Aug. 6, 1918.

2 SHEETS-SHEET 1.

H. D. CHURCH.

MOTOR VEHICLE.

APPLICATION FILED NOV. Is. 1913.

' Patented Aug. 6, 1918 2 SHEETS-SHEET 2- [NI/enlar- 2549 (/75 Zorne y,

Barton) 1). cnuncn,

or DETROIT, MICHIGAN, nssrenon 'ro PACKARD moToR'caJe COMPANY, ornnrnorr, Mrcmeen, A CORPORATION or MICHIGAN.

MOTOR-VEHICLE.

I Specification of Letters Patent.

Application filed November 13,1913. ,seria1m'.soo,soa. p

To all whom it may concern:

Be it known that'I, HAROLD D. CHURCH,

a citizen of the United States, and resident of Detroit, Wayne county,State of Michigan, have invented certain new and useful Improvements inMotor-Vehicles, of which the following is a specification.

This invention relates to motor vehicles and particularly to the brakemechanism of such vehicles.

The salient object of the present invention is to produce a brakingmechanism for motor vehicles in which a given movement of the brakelever will cause a certain extent of movement of the brakeshoe towardthe brake drum and a further movement of said leverthrough the samenumber of degrees will cause a further movement of the brake shoe to anequal extent.

In carrying out the above object a uniform motion cam is employed forthe purpose of expanding the brake shoe against the surface of the brakedrum. Bythe use of such a cam, the brakes maybe adjusted for wearwithout altering in any way theleverage between the bra e operatinglever and the brake shoe. In other words, when the brakes are newlylined there will be a certain la verage between the brake operatinglever and the brake shoe and after the lining has'worn to a certainextent, the ends of thebrake shoe may be further separated'for thepurpose of bringing them in contact with the brake drum, and'theleverage during this further separation will be exactly ora1pproximately the same as when the bra e lining was new.

Another object of the invention is to produce a motor vehicle brakingmechanism of simple and eflicient construction, and of few and lastingparts.

Other objects than those specified above I will be apparent from thefollowing description taken in connection with the drawings which form apart of this specification, and in which: e p

Figure 1 is a section through the brake drum of the right wheel of amotor vehicle showing the brake shoes and some parts of the vehicle inelevation;

, Fig. 2 is a section approximately on the line 2-2 of Fig. 1;

Fig. 3 is 'a diagrammatic view on an enlarged scale showing one half ofthe uniform motion cam for operating. the brake;

Fig. 4 is a diagrammatic enlarged view" showing the contiguous endsofthe brake shoes and the expanding cam; and

Fig. 5 is a view similar to Fig. 4 but with theparts in a differentposition.

Referring to the drawings, 10 represents one of the'side members of thevehicle frame which ISSUPPOItBd upon the springs 11 from the axle12. Oneof thewheels 13 of the vehicle is shown and the brake drum ofthe otherwheel is shown in section at 14'. 15 is theradius or distance rodextending from the axle to the frame. v

The stationary part of the axle 12 is in the form of a tube as shown'inFig. 2 and within this tube are the axle" sections 16 which are suitablyconnected to drive the wheels 13, which are shown as mounted in bearings17 on the outside of the tubular axle 12.- (See Fig. 2).

Secured to, or formed as a part of the axle 12. is a brake supportingmember havhereinafter described. The arm 18 has adjacent the outer end aboss 18 in which a transverse member or pin 20 is suitably fitted. Thistransverse member is secured at a point between its ends to the boss 18and extends on either side of its supporting arm.vv It will also be seenthat the member 20 is'secured against movement by means of a clampingbolt 20 and has wearing pieces orblocks 21 suitably arranged on the endportions thereof. Secured to the brake shoe 19 or formed integraltherewith are lugs 22 which are .adaptedto be slidingly mounted on theblocks or wearing pieces Patented Aug. 6, 1911s.

21. This method of mounting permits the central part of the brake shoeto slide radially of the axle toward and from the brake drum 14, andsprings 23 retain the brake shoe yieldingly out of contact with thebrakedrum. The brake shoe is provided with a-brake lining 19 and anadjustable set screw 24: determines the extent to which the brake shoemay be permittedto'be retracted from the drum.

The opposite-arm 18 has a bearing 25 for a rock shaft 26 upon one end ofwhich is an operating arm 27 and upon the other end of which is a cam 28which is positioned between the opposing ends 29 of the brake shoe 19.These. ends 29 are arranged adjacent each other and are adapted toberex- I panded by means of the cam 28 so: that the 1 brake shoe will bepressed intocontact with the brake drum 14, whichwill be clearlyunderstood from the drawing. The ends 29 are provided'with suitablewearing pieces 30, and a spring 31 is connected-to the ends for holdingthem yieldingly in contact with the cam 28 and therefore out of contactwith the brake-drum, 14. The arm 27 which, P?

- crates therock shaft 26 is itself operated 7 through a connecting rod32 which is adjustthe rearward movement of the lower arm of the brakeoperating lever 34. Thus all of the connections between the brake andthe operating lever 34 are held in tension by the spring 31.-

The shape or form of the cam 28 is clearly illustrated in Figs. 3, 4 and5, and it may be described as a uniform motion cam. In

other words, the surface of the cam is of special spiral form instead offlat or rectangularas heretofore. For instance, in Fig. 3, a, b and 0represent three separate points of contact of the cam with the wearingpieces 30 of the end 29 of the brake shoe. d, e, and f represent threepoints 22?} apart on a circle drawn about the axis 28 of the cam. Thecam is so formed that the line 0-7 is exactly as much longer than theline b'e as the latter is longer than the line ad. Thus when the cam isrotated 22, or the distance from d to e the shoe has been moved acertain distance, and if the cam is rotated another 22% or the distancefrom e to f the shoe is moved the same distance as when the cam wasrotated from d to 6. Thus, if-it takes the first said movement of 22} ofthe cam with the rock shaft 26 to set the brakes from their normalinoperative position when the brake lining is new, it will ,take thesame movement only of-the rock shaft 26 to fully apply the brakes afterthe brake lining has .worn considerably and the adjustmenttaken upthrough the device 33. Thus it will be seen that the cam 28 has the sameleverage under one of the above referred to conditions as under theother.

The operation of the cam upon the ends of the brake shoe is particularlywell illustrated in Figs. 4 and 5. In Fig. 4 the full lines representthe brake in inoperative position and with a new lining 19. In dottedlines the cam has been turned sufficiently to fully apply the brakeshoes to the brake band-and itwill be seen that the cam has.

been rocked approximatelyof'afull circle' or 22?; degrees. In Fig. 5:the full lines show the brake shoe in its normal inoperative positionand with the lining. 19' con siderablv worn. In this case the, cam hasbeen adiusted so that in its inoperative position itv is in exactly thesame position as is.

shown in dotted lines in Fig. 4. If then, the cam 15 rocked through thesame number of degrees as in Fig. 4, that is, of a .full

verage of the cam over the brake shoes is the same.-

A- specific embodiment of the invention has been described: in detailand will'be specifically claimed, but itwill be understood that theinvention is not limited to the exact details of construction shown, asit will be apparent that changes may be made without departing from thespirit or scope of the invention.

Having thus describedmy invention, what I claim and desire to secure byLetters Patent is:

1. A brake mechanism comprising a brake drum, a brake, and a uniformmotion cam for operating said brake. a

I 2. A brake mechanism comprising a brake drum, an expanding brakecooperating with said drum, and auniform motion cam for operating saidbrake.

3. A brake mechanism comprising abrake drum, an expanding brakecooperating. with said drum, and a double faced uniform motion cam foroperating said brake.

4. A brake mechanism comprising a brake drum, a shoe adapted tocooperate with said drum, a plate cam for operating the shoe, and alever for operating the cam, the cam being formed so as to cause amovement of the brake shoe to a certain extent upon the movement of thelever through a certain number of degrees and tocause a further movementof the brake shoe to an equal extent upon the further movement of thelever through the same number of de recs.

5. In a motor vehicle the com ination with a brake drum and the brakeshoe cooperating therewith, of a plate cam for operating the brake shoe,a lever for operating the cam, and an adjustable connection between thelever and the cam, said cam being formed so as to cause a uniform motionof the shoe within the limits of movement ofthe cam.

6. A brake mechanism comprising, in comrat bination with an axle, asupporting member 13o arm, spring means for so moving said. shoe in onedirection and adjustable means for limiting said movement.

I 7.. Abrake mechanism comprising, in com-- bination with an axle, asupporting membermounted on said'axle and having a radially extendingarm, a transverse member secured between its ends to said arm, and abrake shoe mounted on said transverse member whereby said shoe ma bemoved radially of said arm, and adjusta said. movement.

8. A brake mechanism comprising, in combination with an axle, asupporting member arran ed on said axle and having a radially 1e meansfor limiting exten ing arm, said arm having a boss; formed thereon adacent the end thereof, a pin secured in sai boss, and a brake shoemounted on the opposite ends of said in.

9. A brake mechanism comprising, 1n combination with an axle, asupporting member arranged'on said axle, and having a radiallyextending] arm, said arm having a boss' formed adjacent the end thereof,a pin secured in said boss, a brake shoe mounted on the. opposite endsof said pin, and

' adapted for movement radially ofsaid arm.

10. A brake. mechanism combination. with an axle, mounted to rotatethereon, a supporting member mounted on-said axle and having a radiallyextending arm, a transverse member secured between its ends to said arm,wearing pieces arrangedon the ends of said transverse member, and abrake shoe mounted on said wearing pieces, and adapted for movementagainst sa1d drum. Y

'11. A brake mechanism comprisin combination with -an axle, a brake rummounted to rotate thereon a supporting member mounted on said axle andhavinga radially extending arm, a transverse member. secured between itsends to said arm, wearing 'pieces arranged transverse member, a brakeshoe mounted on said wearing piecesand adapted for movecomprism in abrake ru'm ,ment radially .of said axle, and adjustable.-

means for'limitin said radial movement.

on the ends of said In testimony w ereof I a'flix my signature in thepresence of two witnesses.

HAROLD D. CHURCH.

Witnesses:

I. M..WAGNER, Ln ROY J; WILLIAMS.

